What is facebook and other tidbits

Okay, I hate to plead ignorance on this one, but I must. I keep getting these emails that so and so has picked me as a friend on facebook. I go in and confirm that yes I know this person, but I have no clue what facebook is or what it is used for. Anyone? Please email me and let me know, it is driving me crazy.

This weeks highlights:

• We've all kicked the cold, but S brought it back home with him today...yuck
• Mr. Bob the 3rd has passed. We actually leveled with D this time and told him that Mr. Bob was really sick, he keeps insisting that we go get a new Mr. Bob. S and I cannot understand how we have killed 3 Beta fish, they are supposed to lived for 5 years. Will Mr. Bob the Tunafish the 4th survive this craziness?
• Our dog Dolly had another "episode" where it looks like she has had a stroke, but the vet assured us it was no stroke and just age. Not sure how much more of that I can take.
• We booked a room for C's birthday/baptism/homecoming party for May 18th.
• Successfully took both boys many places this week including our favorite lunch spot and a trip to Whole Foods. Yeah for me! Brave or Stupid...you choose.